De Botton's been discussed here before, especially regarding the idea that atheists as such are so alike in their outlooks that they should gather and develop group and community agendas. My own suspicion is that atheists are a job for a black-belt cat herder.

He also seems not to notice that a lot of what he speaks of already exists. An atheist who wants atheist company can get it on the net. Or if social mixing, Humanist organizations and atheist groups so called - and versions of the UU and Episcopalians / Anglicans and other liberal Christian groups, not to mention the non-monastic Buddhists, are often comfortably at home with atheist ideas.

I think his ideas are plausible in the negative sense, interesting to have heard once, but not on the money.

One Thing "Atheists" (rather than from "Athe-ISM") could learn from People of Religious Faith (rather than from "Religion") is that there is great Variation and multiple Possibilities among us, i.e. we're NOT all Rigid, Dogmatic, Ir-Rational, Delusional, Authoritarian, anti-Scientific or ANY of the terrible Things unfairly said/written about us ...